Canon MF455dw printer/scanner/fax: I get an "out of paper" error message, that tray is empty when it is not (either with a little or a lot of paper). Correct paper used. tried unplugging and restarting. Cassette seems to be well and properly loaded and inserted. Removed, checked and reinserted a few times to be sure. However, it WILL print satisfactorily if I feed paper in the manual slot. This started abruptly today. (The only other message is a "low toner" message, although I assume that should not interfere with the paper feeding as long as it is not empty...and, as I noted, the copies fed through the manual feed look fine.) To my naive way of thinking, it would almost seem like the machine is not sensing the presence of paper in the tray??
